This section provides background information related to the present disclosure which is not necessarily prior art.
Internal combustion engines are used to generate considerable levels of power for prolonged periods of time on a dependable basis. Many such engine assemblies employ a boosting device, such as an exhaust gas turbine driven turbocharger, to compress the airflow before it enters the intake manifold of the engine in order to increase power and efficiency.
Specifically, a turbocharger utilizes a centrifugal gas compressor that forces more air and, thus, more oxygen into the combustion chambers of the engine than is otherwise achievable with ambient atmospheric pressure. The additional mass of oxygen-containing air that is forced into the engine improves the engine's volumetric efficiency, allowing it to burn more fuel in a given cycle, and thereby produce more power.
A typical turbocharger employs a central shaft that is supported by one or more bearings and transmits rotational motion between an exhaust-driven turbine wheel and an air compressor wheel. Both the turbine and compressor wheels are fixed to the shaft, which in combination with various bearing components constitute the turbocharger's rotating assembly.
Sub synchronous frequency vibration noise can be a concern in a turbocharger. The semi-floating or fully floating turbo-charger bearing according to the principles of the present disclosure is designed to minimize sub synchronous vibration and maintain the load capacity.
A partial admission turbocharger is provided including a housing and a rotary assembly disposed within the housing and including a turbine wheel and a compressor wheel attached to one another by a shaft. The rotary assembly being subject to aero-load in a lateral direction. A bearing is disposed in the housing and rotatably supports the shaft, the bearing including an inner bearing surface that engages the shaft and an outer bearing surface that engages the housing, the outer bearing surface having a pair of axially extending recessed grooves extending at least partially along the bearing. The pair of axially extending grooves being located perpendicular to the aero-load direction.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.